Bump actions/checkout from 4 to 6

.github/workflows/docs.yaml

@@ -24,7 +24,7 @@ jobs:
     outputs:
       deploy: ${{ steps.set-deploy-output.outputs.deploy }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with: # no need for the history
         fetch-depth: 0
     - uses: actions/setup-python@v5
@@ -72,7 +72,7 @@ jobs:
           python-version: '3.10'
           deploy: true   # Only deploy from this configuration
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: actions/download-artifact@v3
       with:
         name: documentation

.github/workflows/publish.yaml

@@ -12,7 +12,7 @@ jobs:
         os: [ubuntu-latest]
         python-version: ['3.10']
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0 # Includes getting tags
     - name: Set up Python ${{ matrix.python-version }}

.github/workflows/release.yaml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
     - name: Prepare repository
         # Fetch full git history and tags

.github/workflows/test.yaml

@@ -16,7 +16,7 @@ jobs:
         os: [ubuntu-latest] # For demonstration, other OSes are commented out: macos-latest, windows-latest
         python-version: ['3.11', '3.10']
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:  # no need for the history
         fetch-depth: 1
     - name: Set up Python ${{ matrix.python-version }}
@@ -61,7 +61,7 @@ jobs:
         os: [ubuntu-latest]
         python-version: ['3.10']
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:  # no need for the history
         fetch-depth: 1
     - name: Set up Python